Ants’ shit may help feed humanity
About 12.000 years ago humans started cultivate crops. But farming is much older; it is known from fungi farmed by ants, termites or beetles. Leafcutter ants, the best known farmers among insects derive from insects that have been running mould farms based on plant material already 50 million years ago. Farming based on flowering plans is more recent, about 3 million years – on the Fiji Iislands
New research by dr Guillaume Chomicki of Oxford University and his team shows that millions of years of ant faming has changed the fysiology of plants. They harvest seeds from Squamellaria fruit plants, plant them by inserting the seeds in tree bark cracks. They then fertilize the crop (with their own feces) and carefully maintain it until the fruit grows.Then they eat and even live inside the fruits, making full use of their precious crop. In turn, the plants have been “domesticated” to the point where they can’t grow on their own. The ants place their nitrogen rich faeces directly on the plant. This has lead to the evolution of hyperabsorptive structures, ‘warts’ on the inner walls of the plants fruit where the ants nest.. Nutrients from ants end up directly in the plants instead of in the soil. This new insight can offer important possibilities for our struggle for food security..
This way of farming is unique: the ants not only grow their food but also their homes. The plants offer ready holes for the ants to build their nests in. The relation is essential for both parties: the ants have lost the ability to build a nest, like most ants in the tropics have, and the plants are epiphytes, (plants growing on trees without taking food from the tree) missing roots to take up nutrients. They trust the ants supplying nutrients and defence. The plant is a Squamellaria.
The pictures show a plant with the ants’ nest and the inside of the nest.
Dr Chomicki says: “The speed of taking up nitrogen is an important limiting factor for the growth of plants. Most plant including our crops take up nitrogen from the soil and are not naturally exposed to very high concentrations of nitrogen. During millions of years these ants have placed their nitrogen rich faeces directly on the plants. Now we try to figure out the genetic basis of the hyperabsorbing structures in these plants, that can be placed in our crops. In this way we can possibly improve the uptake of nitrogen – and with that the growth.”